I would say fiat price doesn't matter, regardless of whether it's short term or long term. I'm not interested in whether bitcoin goes to $1m by a given date, but rather what I can buy for it. If I can still buy a car, good. If I can only buy a bicycle or a pack of chewing gum for that $1m, then I've lost purchasing power.

Short term price doesn't matter, because we're in it for the long haul. Long term price doesn't matter, because price is only a short term proxy for purchasing power.